Generally, perishable objects such as raw seafood, poultry, meats and dairy products deteriorate with time. One important factor affecting the rate of deterioration is water activity. Water activity affects the shelf life, safety, texture, flavour and smell of foods, as well as the stability of pharmaceuticals and cosmetics. In addition, water activity affects the activity of enzymes and vitamins in foods and the denaturing of fats and proteins, which in turn affects the colour, taste, and aroma of foods.
The water activity is a measure of the energy state of the water in a system. Some factors that affect water activity are water binding strength, dissociation of water, and solubility of solutes in water. Water activity also determines the lower limit of availability for microbial growth. The lower the water activity is or the higher the water binding strength is, the slower the deterioration of the food quality and bacteria growth is. Therefore, it is important to treat the perishable objects and the liquids to prolong the shelf life.
There are various known methods and devices to treat the perishable objects (e.g. cooked food, beverages, raw meat, etc.), to keep the perishable objects fresh. Some conventional devices utilise static magnetic fields to treat a perishable object, such as raw food and alcoholic beverage. These known devices typically use an array of permanent magnets that are arranged on a flat plane surface to perpendicularly project a magnetic field towards the object to be treated.
Some conventional devices utilise magnetic fields created by magnetic interference to treat perishable objects. Similarly, these known devices typically comprise a plurality of magnets arranged in a panel such that a magnetic field created by magnetic interference projects from the panel.
To treat a large object, such known devices may comprise several planes/panels of magnets and/or a large number of magnets in order to project a magnetic field that extends sufficiently to cover the object to be treated. However, having several planes/panels of magnets and/or a large number of magnets not only increases the weight and bulk of the device, the cost of manufacturing the device also increases. These disadvantages make the known devices not practical for commercial applications. Further, for a given size and weight, the magnetic field generated by the known devices may not be strong enough to effectively treat the perishable objects.
Therefore, there exists a need to provide a device for treating perishable objects or liquids and method of fabricating the device to address or overcome at least one of the above problems.